At present industry is in great need of for a substantial increase in the speed of piston compressors along with the retention of their high economic efficiency. Since valves are principal elements determining the resistance in the gas channel or path of the piston compressor and the losses arising therein are the most of the energy losses in the compressor, it is necessary to increase flow sections of the valves without impairing their reliability and increasing the overall dimensions.
Known in the prior art are straightway valves solving this problem, for example the straightway valve in accordance with U.S. Pat. No. 3,786,833 patented in 1974 (selected as a prototype) that comprises a housing made from interconnected stiff members, each still member having on its one side an intake channel and a seat surface arranged opposite the intake channel and a seat of another stiff member, and closing members made as toothed plates pinched between adjacent stiff members of the housing.
This straightway valve allows its flow section to be enlarged without increasing its overall dimensions since the multitooth plate has an extended length of the outlet slot.
However, the multitooth plates are complicated in production since they require a substantial complication of the dies. Furthermore, their production requires a very wide strip of thin thickness, possessing a high strength and a high elasticity. Moreover, because of anisotropy of the strip material a part of the teeth is unfavourably oriented with respect to the direction of rolling. This reduces the strength of the plates and, hence, the reliability of the valve.
In addition, microcracks are developed at the tooth edges during the die forging of the plates. This reduces the service life of the plates and, hence, of the valves as a whole.
The technique of vibration tumbling by means of an abrasive material in a rotating drum is an effective method for strengthening the plates. However, this method of strengthening is unusable for thin multitooth plates weakened by slots between the teeth.
When the pack of valve members is squeezed, small crumplings of the portion of the seat surface are formed, and a shoulder is formed along its border. This shoulder bends the plate teeth towards the limiting surface and causes gas leakages, i.e. leads to a reduction in the valve efficiency.